What It Will Take to Win in 2016

Democrats have some advantages, but history favors the Republicans.

As Labor Day nears, let’s step back from the daily jousting over the parties’ presidential nominations and examine the fundamentals that will shape the race in 2016.

Some basics favor the Democrats. Relative to 2012, the share of the electorate commanded by minority voters—principally Hispanics, African-Americans and Asians—will continue to increase. This shift will be especially pronounced in states such as Florida and Nevada, where large numbers of Hispanics are reaching voting age. Millennial voters (young adults of all...